I. Field of the Invention
The present invention relates generally to remote control devices and, more particularly, to an infrared remote control device.
II. Description of the Prior Art
Many modern cameras include an electrically activated shutter and motor driven film advance. Typically, these cameras include two electrical terminals or jacks in which completion of the electrical circuit between the terminal both activates the shutter to take the picture, as well as advances the film to the next frame.
In many situations, it is desirable to activate a camera from a remote location For example, in wildlife photography it is frequently desirable to establish the camera location and then activate the camera from a remote position. In doing so, the photographer can avoid disturbing the wildlife while still obtaining the desired photographs.
There have been a number of previously known cameras which are activated by remote controls. Some of these remote control cameras utilize a hard wire system while others utilize a radio link. In at least one previously known remote control device for a camera, an infrared signal is used as the communication link to activate the camera from a remote position.
One disadvantage of these previously known cameras with remote control units is that they are very expensive in cost. The reason for this high cost for the remote control units, particularly with infrared remote control units, is twofold.
First, the previously known cameras with infrared remote control units include both the infrared transmitter which is operated by the photographer at the remote position as well as the infrared receiver at the camera. Consequently, these previously known devices have required the purchase of both the receiver and the transmitter.
Secondly, it has been necessary for the infrared receiver of the camera to differentiate between the infrared signal from the transmitter and ambient infrared signals which may be present in the atmosphere. Typically, the transmitter transmits a coded sequence of pulses to the receiver. The receiver in turn, upon receipt of the infrared signal, decodes the series of pulses and then utilizes circuitry to determine whether the received infrared signal constitutes a valid signal from the transmitter or is merely ambient infrared radiation. In either case, both the coding of the infrared signal at the transmitter, as well as the decoding of the infrared signal at the receiver, increases the overall cost of the remote control device.